Difference in the polysomaty degree during fruit development among plants with different ploidy levels produced by artificial chromosome doubling of a pepper ( Capsicum annuum) cultivar ‘Shishitou No. 562’

Abstract

Polysomaty status of fruit pericarp was compared between a diploid cultivar of pepper ( Capsicum annuum ‘Shishitou No. 562’) and its artificially induced triploid and tetraploid plants. In pepper fruits of different ploidy levels, fruit size as assessed by fruit length reached a plateau from 3 to 4 weeks after anthesis, and the maximum fruit length of triploid and tetraploid fruits was about 43% and 88% of the diploid counterpart, respectively. However, the maximum fruit diameter of both triploid and tetraploid plants was almost the same as that of diploid plant. Polysomaty status of fruit pericarp increased during fruit development and the maximum DNA content of the pericarp cells in the diploid, triploid and tetraploid fruits showed 64C, 96C and 128C, respectively. These results indicate that the same number of endoreduplication is programmed to occur in pepper fruits irrespective of the difference in the ploidy level of plants.